Refining of aromatic hydrocarbons with acid-acting metallic halides



Patented Dec. 24, 1946 REFINING F AROMATIC HYDROCARBONS WITH ACID-ACTINGMETALLIC HALIDES Frank J. Soday, Swarthmore, Pa., assignor to The UnitedGas Improvement Company, a corporation of Pennsylvania No Drawing.Application February 10, 1943,

Serial No. 475,438

10 Claims. (01. 260-674) This invention is concerned with the refiningof aromatic hydrocarbons. More particularly, this invention removal ofunsaturated hydrocarbons from aromatic hydrocarbons, or fractions and/ormix-' tures containing aromatic hydrocarbons.

An object of the present invention is the removal of impurities fromaromatic hydrocarbons by the application thereto of successive portionsof acid-acting metallic halides. Another object of the invention is theprovision of methods for the conversion of unsaturated hydrocarbonspresent in aromatic hydrocarbon fractions into resinous and/or oilypolymers possessing considerable industrial utility.

Other objects and advantages of the invention. will be apparent to thoseskilled in the art upon an inspection of the specification and claims.

In the various processes for the manufacture of artificial gas such asoil gas, carburetted water gas, or coal gas, considerable quantities oftar are produced, and the gas contains substantial quantities of readilycondensible materials.

These condensates, as well as the light oil obtained upon distillationof the tar, are sources for many hydrocarbons, including aromatichydrocarbons such as benzene, toluene, xylene, and

the miscellaneous hydrocarbons which are commonly designated as solventnaphtha.

With ordinarymethods of fractional distillation as now practiced, it isimpossible to separate these compounds in a substantially pure statebecause of the presence of other -'materials which, are either ofsimilar boiling point or are capable of forming azeotropic mixtures withthe desired hydrocarbon. The impurities present in the aro- Y matichydrocarbon fractions are essentially unsaturated in nature, and areusually present in considerable quantities.

Typical aromatic fractions obtained by the fractionation of light oilobtained in the pyrolysis 'of petroleum 'oil will contain from 5 to byweight of unsaturated hydrocarbons, which is unusually high. Theseunsaturated hydrocarbons must be removed from the aromatic fractionsbefore they can be used for many. industrial purposes. This has provedto be a very difllcult undertaking due to the necessity of removingunusually large quantities of unsaturated hydrocarbons from therespective fractions.

Theprocesses which have been developed for the purification of aromatichydrocarbon fractions with polymerizing agents, such as AlCla, are ofparticular interest as they offer a convenient method of converting theunsaturated hydrocarpertains to the metallic halide such as aluminumchloride does a not refine the aromatic hydrocarbon sufficiently bonspresent in the aromatic hydrocarbon fractions into products which have apotential commercial value. In contrast to this, the usual" processemployed for the purification of crude aromatic hydrocarbon fractions,namely, processes'based upon the use of sulfuric acid, results in theproduction of a black, viscous acid sludge of no value. In many cases,the disposal of this acid sludge is a very serious problem, as it cannotbe. indiscriminately dumped due to its highly corrosive nature.

I have found that a single treatment ofa crude aromatic fraction with'an'acid-acting to permit it to pass the usual commercialspecifications. In addition, the high temperatures customarily' employed78 0.) results in the conversion, of the unsaturated hydrocarbonspresent to darli, viscous polymers of low molecular weight.

I have discovered that crude aromatic hydro-. carbon fractions can berefined with acid actin metallic halide catalysts such as aluminumchloride to meet. the most exacting industrial specifications byconducting the refining operations 1.

in at least two stages, preferably removing the resinous polymers formedbetween the successive treating stages. In addition, the unsaturatedhydrocarbons present 'in the crude'aromatic fraction areconverted intotwo valuable'products, namely, a high-melting resin of good quality, andan oily polymer. The process preferably is carried out at temperaturessubstantially below N The high melting resin is usually obtained dur ingthe initial treating process and comprises the major portion ofthe'unsaturated hydrocarbons is formed from the remaining unsaturatedhydrocarbons present in the crude fraction." By varying the treatingprocess, it is possible to produce to obtain a mixture of oily polymersand high- .amixture of high-melting resin and oily polymer from the,initial refining step, the high-melting resin predominating in themixture. It.is also possible to operate-the process in such a way asmelting resin from the succeeding treating stages, the oily polymerpredominating.

For certain industrial applications, the use of amlxture of these twopolymers in a given proportion may be found to be more advantageous thanthe' use of ei'therpolymer alone. The proc- -ess described herein .canbe controlled in such a way asto produce a mixture ofpolymers of thedesired composition. For certainother appllcations, however, thehigh-melting resin or the oily polymer may alone be required,'in whichcase they may be separated from their respective mix-.

tures, preferably by distillation. Distillation with Y steam, preferablyunder reduced pressure, has 1 been found to be a very satisfactorymethod.

By' a suitable choice of operating conditions, it is possible tobbtainthe high melting resin in relais removed before adding a fresh quantityof catalyst. Apparently the hydrocarbon polymer present in the solutiondiminishes the activity of the freshly-added catalyst, such as by theformation of loose complexes between the hydrocarbon polymer-AlChcomplexes present in the solution and a portionor all of the new chargeof aluminum chloride.

tively pure form from the initial refining opera tion. In addition,refining process canbeopers from the succeeding stages of the treatmentcon-- sists almost entirely or the oily polymer. This ated in such a waythat the product obtained procedure eliminates the necessity ofseparating the polymers obtained from the process.

On the other hand. the refining of crude aromatic hydrocarbon fractionswith acid-acting metallic halides such as aluminum chioridein successivestages, but without intermediate removal of the polymer formed duringeach of the treating stages, results in a mixture containing all of thehigh-melting resin and the oily polymers formed during the refiningoperations. In case it is desired to separate the components of thispolymeric mixture, the distillation step previously described ispreferably employed.

It has also been found that a multiple treating process in which thepolymerized hydrocarbons are removed between the successive treatingstages results in the production of refined aromatic hydrocarbons ofbetter quality than the methoddiscussed in the preceding paragraph,

in which the polymer formed is only removed at the end of the treatingprocess.

The improved efilciency of the multiple stage treating process over thesingle stage treating.

process is based upon the following theoretical considerations. Theaddition of an acid-acting metallic halide such as aluminum chloride toa system containing unsaturated hydrocarbons results in the primaryformation of aluminum The quantity or acid-acting metallic halide suchas aluminum chloride required for refining crude aromatic hydrocarbonfractions ranges from 0.5 to 5.0%, although from .1 to 3% will be foundto be sufilcient in practical all cases. This quantity of catalyst isconsiderably less than the I quantity normally used'in the single stagealuminum chloride process.

Any desired treating temperature can be em- 9 ployed,'althoughtemperatures in the range of 1 to 10 hours.

0-90 C. are more often used. I find that the use of treatingtemperatures in the range of 20-60 0., and more particularly in therange of 30-50 0., gives very satisfactory results. Adequate coolingprovisions must be made in order to control the temperature within thelimits desired. In J general, the use, of elevated treating temperaturesresults in a more complete removal of the unsaturated hydrocarbonspresent, but with the production of resinous polymers of inferiorquality, while the use of very low treating temperatures results in anincomplete removal of the unsaturated hydrocarbonspresent, accompaniedby the production of resinous polymers of excellent quality. The use ofthe preferred treating temperaof a good 1 tures will result in theproduction grade of refined aromatic hydrocarbons, as well as resinousproducts of good quality.

The treating time employed usually varies from treating periods resultsin the more complete chlorideunsaturated hydrocarbon complexes 1 which,in turn, act as the actual polymerizing agents. The reaction is of thechain type. the unsaturated hydrocarbons presentbecoming attached to theAlCl3 complex originally formed,

resulting in an increase in the length of the hydrocarbon chain attachedto each aluminum chlo- I ride molecule. As the length of the hydrocar--bon' chain increases, its activity proportionally decreases.Consequently, the rate of removal of unsaturated hydrocarbons from thesolution to form resin decreases at a fairly rapid rate, and

. at the end of the treating process the point of minimum concentrationof unsaturated hydrocarbons in-the solution coincides with the point ofminimum catalytic activity. As a result the aromatic hydrocarbon, oraromatic hydrocarbon fraction, subsequently obtained containsconsiderable quantities of unsaturated hydrocarbons, and does. not meetthe usual specifications for commercial grades of the correspondingrefined aromatic hydrocarbons.

I The multiple-stage treating process counter-v acts thediminishedactivity of the catalyst near the end of the treatingprocessby the addition of a fresh quantity of catalyst. Theunpolymerized,

unsaturated hydrocarbons present in the solution at this point are thenpolymerized by the fresh catalyst.

As previously pointed out, the multiple-stage 1 treating process givesthe best results if the polymer formed during th first stage of theprocess elimination of the unsaturated hydrocarbons present. v

' The refining agents which have been found to be of value in thisprocess comprise the .acidacting metallic halides, as well asacid-acting metallic halide-organic solvent complexes.v Examples ofthese catalysts are A1013, FeClz, ZnCla,

AlBra, BF: BCla, AlCla.organic ether complex,

BFaorganic ether complex, and the like. Since the metallic halide is theactive component whether or not it is in the form of a complex,

these catalysts are defined collectively as acid-- very narrow boilingcuts may be refined by this process, the aromatic hydrocarbons securedthen requiring no further fractionation to meet the usual specificationsfor refined products.

The process has been found to be very satisfactory for the purificationof benzene, toluene and xylene aromatic fractions.

The polymerized solution is usually treated with a hydrolyzing agent todecompose the catalyst present, followed by the separation of theinsoluble material present by suitable means, such general, theuse ofextended as filtration. The polymer is then separated from the refinedhydrocarbon fraction, usually f by distillation. The aromatic fractionmay then be fractionated in an efllcient column to produce the process.1

Exmm 1 A 1500 cc. portion of an aromatic hydrocarbon fraction obtainedby the condensation of oil gas, and containing 8.6% by weight ofunsaturated hydrocarbons, was treated with 105 cc. of 96% H2804(equivalent to 1.07 lbs. ofHzSOr per gallon) according to the standardmethod outlined in'the Gas Chemists Handbook. The solution was cooledand vigorously agitated by means of a turbo-mixer during the entiretreating operation. The sludge was removed at the end of the acidtreating process, the refined solution then washed with water, and thenneutralized with a 30% solution of sodium hydroxide. The hydrocarbonfraction then was dried and fractionated in a Fenske-type columnpossessing 11 theoretical plates, using a reflux ratio of 10:1. Thefollowing results were secured.

A 2000 g. portion of the same aromatic fraction used in Example 1 wasplaced in a three-neck round bottom flask provided with a refluxcondenser and an agitator. Approximately 86 grams of anhydrous aluminumchloride (4.3% byweight of the fraction to be refined) was added and themixture agitated for a period of 3 hours at a temperature of 30-40" C.The temperature then was raised to 50 C. and the reaction continued foran additional period o'f'three hours. The polymerized solution then wastreated with a 30% solution of sodium hydroxide, filtered,.and themixture distilled on an oil bath at a temperature of 170 C. Thedistillate then was fractionated in the column previously described. The

following results were secured.

EXAMPLE 3 A 2000 g. portion of the same aromatic fraction.

used in Example 1 was treated with 20.0 grams of aluminum chloride (1.0%by weight of the' fraction to be refined) at a temperature of 20-30 C.for a period of one hour. The temperature then was increased to 50 C.and the treatment continued for an additional period or three hours.

An additiona1 1.0% portion ride (20.0 g.) was added to the reactionmixture at this point, and the treatment continued .for a further 3 hourperiod at a temperature or 50 C. The-solution then was neutralized witha 30% solution of NaOH, dried, and fractionated, in the mannerpreviously described. The following re- Exmna 4 A 2000 g. portion of thesame aromatic fractionused in Example 1 was treated with 20.0 g.

of AlCla (1.0% by weight of the fraction'to be refined) 'at atemperature of 20-35" C. during a period of 4 hours.

A slight excess of 30% NaOH solution was added to the reaction flask,and the mixture agitated for a period of two hours. The unreactedhydro-- carbon fraction was then separated from the resinous polymer bydistillation, andthe distillate dried over lime.

The distillate was again treated with 20.0 g.

(1.0%) of A1013 for a period of approximately one hour at a temperatureof 20-35" C. The temperature was increased to 50C. at this point and thereaction continued for an additional period or three hours. Thepolymerized solution was hydrolyzed with a 30% solution of NaOI-I, theunchanged hydrocarbon fraction separated from the resinous polymers, andthe distillate dried over lime. It then was fractionated in the mannerpreviously described. The following results were secured.

Per cent by Barretts Component weight of acid wash charge stock color 1.Distillate 87.0 (0) 2 benzol. 53. 6 1 l (0) 2 t01u0l- 19.6 1 2. Resinouspolymers -13. 0

The data indicate that the refined be'nzol and toluol secured was ofexceptional purity, as measured by the low acid wash colors of therespective fractions secured.

EXAMPLE 5 A 1500 cc. portion of an aromatic hydrocarbon fractionobtained by the distillation of tar obtained as a by-product in the oilgas process, and containing 8.6% by weight of unsaturated hydrocarbons,was treated with cc.-of 96.0% H2804 (equivalent to 1.07 lbs. of H2804per gallon) according to the standard method described in the GasChemists Handbook. The solutionwas cooled and vigorously agitated duringthe entire treating process. The sludge was removed at the end of theacid treating process, and the refined solution then washed with waterand neutralized with af 30% solution of sodium hydroxide. Thehydrocarbon fraction thenwas dried and ractionated in a Fenske-typecolumn possessing 11 theoretiof aluminum chlo- Per cent by I weight ofComponent chargestock co r a; 2 benzoL- 26. 3 6% 2 toluol--- 44. 3 5udge 11 6 Exsuru: 6

A 2000 g. portion of the same aromatic fraction used in Example 5 wasplaced in a threeneck round bottom flask provided with a refluxcondenser and an agitator. Approximately 86 g. of anhydrous AlCls (4.3%by weight of the fraction to be refined) was added and the mixtureagitated for a period of 3 hours at a temperature of 30-40 C. Thetemperature then was raised to 50 C. and the reaction continued for anadditional period of three hours. The polymerized solution then wastreated with a 30% solution of sodium hydroxide, filtered, and themixture distilled on an oil bath at a temperature of 170? C.

- The distillate then was fractionated in the column previouslydescribed. The results secured were as follows:

A 2000 3. portion of the same aromatic fraction used in Example 5 wastreated with 20.0 g. of aluminum chloride (1.0% by weight of thefraction to be refined) at a temperature of 20-30 C. for a period of onehour. The temperature then was increased to 50 C. and the treatmentcontinued for an additional period of three hours. An additional 1.0%portion of A1013 (20.0 g.) was added to the reaction mixture at thispoint. and the treatment continued for a further 3 hour .period at atemperature of 50 C.

The solution then was neutralized with a 307 solution of NaOH, dried,and fractionated in the manner previously described. .The followingresults were secured: I

Exmrns 8 A 2000 8. portion of the same aromatic fraction used in Example5 was treated with 20.0 g. of AlCla (1.0% by weight of the fraction tobe refined) at a temperature of 20-35 C. during a period of 4 hours.

A slight excess of 30 NaOH solution was added to the reaction fiask, andthe mixture agitated for a period of two hours. The unreactedhydrocarbon fraction was then separated from the resinou's polymer bydistillation, and the distil-' late dried over lime.

The distillate was again treated with 20.0 g.

8 I (1.0%) of MCI: for a period of approximately one hour at atemperature of 20-35' C. The temperature was increasedto 50 C. at thispoint and the reaction continued for an additional period 7 of threehours. The solution was hydrolyzed with a 30% solution of NaOH, theunchanged hydrocarbon fraction separated from the resinous p01- ymers,and the distillate dried over lime. It then was fractionated in themanner previously described. The following results were secured.

C ponent a id h charge stock cola- 1. Distillate 89.2 Ea) 2 benwL. 30.:1 0) 2 toluol--- 45. 0 1 2. Resinous polymers 10.8

toluol secured was of exceptional purity, as measured by the low acidwash, colors of the respective fractions. 7

It will be noted that Examples 1 and 5 are ex.

.The data indicate that the refined benzol and amples of standardsulfuric acid refining methods. Examples-2 and 6 are examples of asinglestage A1013 treatment, Examples 3 and 7 are examplesof a two-stageAlCla treatment without intermediate removal of the polymer formedbetween the successive treating stages, and Examples 4 and 8 areexamples of a-two-stage A101:

treatment with intermediate removal of the polymers formed in thetreating process.

It will be noted also that only 2% of the cataiyst is required inExamples 3 and '7, as com- A sample of the resinous material obtained bythe aluminum chloride treatment previously described 'Was steamdistilled under reduced pressure. The resinsecured had a melting pointof 147 C. as measured by the standard A. S. T. M. ball and ring method.0 In this connection, it is well to point out that the resin obtained asa result of the refining process disclosed .herein contains substantialproportions of aromatic hydrocarbon residues. Presumably, the aromatichydrocarbon reacts with at least a portion of theunsaturatedhydrocarsuch reaction products to form resinous polymers. The presenceof aromatic hydrocarbon residues in such'resinous polymers confersvaluable soluility and stability characteristics thereto.

A standard 15 gallon varnish was prepared 1 Cobalt, manganese, and leaddrier.

Cooking procedure The mixture of resin and China-wood oil was placed ina copper beaker and heated to atemperature of 400 F. during a period of20 minutes. The mixture was then heated to a temperature of 560 F.during a period of 10 minutes. and held at this temperature for anadditional period of 3 minutes. It was allowed to cool to 535 1"; heldat this temperature for a period of 6 minutes, chilled to 400 F. (bypartially immersing the beaker in water) and reduced byiadding thesolpared with 4.3% in Examples 2 and 6, to secure products having betteracid wash colors.

bons present, followed by the polymerization of anaaeo" vent naphtha.The drier was stirred into the I varnish when it reached roomtemperature.

The product was a clear, light colored yarnish with excellent coatingproperties. .It can be used to coat metals, wood. and other surfaces.

In addition to China-wood oil, other drying oils least one hour to,cause the formation of resinous polymer from a portion of saidpolymerizable unsaturated hydrocarbon material, neutralizing said suchasoiticica oil, perilla oil, linseedoiLisomerizedlinseed oil, dehydratedcastor oil, soya bean oil, fish oil, sardine oil, menhaden oil,synthetic drying oils, and the like, may be employed inthe preparationofvarnishes and other coating compositions irom my new resins.

Other ingredients also may be added to suchv compositions, such assolvents, plasticizing agents, pigments, driers, and the like.

In addition to removing unsaturated hydrocara catalyst, separating'saidpolymer and said' aromatic hydrocarbon material from the resultingreaction mass. and from each other, thereafter contacting said aromatichydrocarbon material with a further quantity of from 1% to 3% by weightof said contaminated aromatic hdrocarbon material of aluminum chloridecatalyst under temperature conditions in' the range of 20 C.

. to 60 C, for a period of at least one hour there- .by causing theformation of oily polymer from b the remaining polymerizable unsaturatedarohung, the refining process described herein also While variousprocedures and formulas have' been particularly. described these are ofcourse subject to considerable variation. Therefore, changes, omissions,additions, substitutions, and] or modifications may be made within thescope of the claims without departing from the spirit of the invention.

I claim:

. said contaminated benzene with from 0.5% tov benzene with afurtherquantity of from 0.5% to.

1. A process for refining aromatic hydrocarbon material boiling below400 C. and contaminated with polymerizable impurity of similar boilingpoint to said aromatic hydrocarbon material which comprises contactingsaid contaminated to 5.0% by weight of said contaminated aromatichydrocarbon material of an acid-acting metallic.

halide catalyst at a temperature between 0C.

and 80 C. for a period of at least one hour thereby'causing theformation of resinous polymer from a portion of said impurity,neutralizing said catalyst, separatingsaid polymer and said aromatichydrocarbon material from the resulting reaction mass and from eachother, thereafter contacting said aromatic hydrocarbon material withfrom 0.5% to 5.0% by weight of said contaminated aromatic hydrocarbonmaterial of additional acid-acting metallic halide catalyst at atemperature in the' range of 0 C. to 80 C. for a period of at least onehour to remove further'impurity in the form of oily polymer,neutralizing said additional catalyst and recovering saidaromatic'hydrocarbon material in purified form from the resultingreaction mass.

2. A process for the purification of aromatic hydrocarbon material ofthe benzene series contaminated with impurity including polymerizableunsaturated hydrocarbon material of similar boiling point to saidaromatic hydrocarbon material, said aromatic hydrocarbon materialboiling below 400 0., which comprises contacting said contaminatedaromatic. hydrocarbon material with from 1% to 3% by weight of saidcontaminated aromatic hydrocarbon material of aluminum chloride catalystat a temperature in the range of 20 C. to 60 C. for a period of-ataromatic hydrocarbon material with from 0.5%

matic hydrocarbon material present, neutralizing said further quantityof catalyst and recovering said aromatic hydrocarbon material in moreconcentrated form from the resulting reaction mass.

3. A process for refining benzene contaminated impurity includingpolymerizable un- I saturated hydrocarbon material of similar boilwithing point tobenzene, which comprises contacting 5.0% by weight of saidcontaminated benzene of an acid-acting metallic halide catalyst at atemperature in the range of 0 C. to C. for a period of one hour to-causethe formation of resinous polymer from atleast a portion of saidunsaturated hydrocarbon material, neutralizing said catalyst, separatingsaid polymer and said benzene from the resulting reaction mass and fromeach other, thereafter contacting said 5.0% by weight thereof ofacid-acting metallic halide catalyst'at a temperature in the range of 0-C. to 80 C. for a period of at least one hour .to cause the formation ofoily polymer from'the remaining unsaturated hydrocarbon -material,

neutralizing said further quantity of catalyst, and

recovering benzene in more concentrated form from the resulting reactionmass.

4. A process for refining toluene contaminate with saturated hydrocarbonmaterial of similar boiling point to toluene, which comprises,contacting said contaminated toluene with from 0.5% to 5.0% by weight ofsaid contaminated toluene of an acid-acting metallic halide catalyst ata temperature in the range of 0 C. to 80 C. for a,

period of at least one hour to cause the formation of resinous polymerfrom a portion of said unsaturated hydrocarbon material, neutralizingsaid catalyst, separating said polymer and said toluene from theresulting reaction mass and from each other, thereafter contacting saidtoluene with a further quantity of from 0.5% to 5.0% by weight thereofof acid-acting ,metallic halide catalyst at a temperature in the rangeof 0 C. to 80 C. for a, period of at least one hour to cause theformation of oily polymer from the remaining unsaturated hydrocarbonmaterial, neutralizing said further quantity of catalyst, and recoveringtoluene in more concentrated form from the resulting reaction mass. 3 r

5. A process for refining a mixture of benzene and toluene contaminatedwith impurityincluding polymerizable unsaturated aromatic hydrocarbonmaterial of similar boiling point to said mixture, which comprisescontacting said contaminated mixture of benzen and toluene with from0.5% to 5.0% by weight of said contaminated mixture of an acid-actingmetallic halide catalystat a temperature in the range of 0 C. to 80 C.for a period of one hour to cause the formation of resinous polymer fromat least impurity including polymerizable unhydrocarbonmateriaLneutralizing said catalyst, separating said mixture ofbenzeneand toluene from the resulting reaction mass including said ipolymer, thereafter contacting said mixture of benzene and toluene witha further quantity of from 0.5% to 5.0% by weight thereof of acidactingmetallic halide catalyst at a temperature inthe range of C. to 80- C.for a period of at least one hour co cause the formation of oily polymerfrom the remaining polymerizable unsaturated hydrocarbon material,neutralizing said further quantity of catalyst and recovering a mixtureof benzene and toluene in more concentrated form from the resultingreaction mass.

6. A process for'the recovery of refined benzene from a light oilfraction containing benzene together with polymerizable unsaturatedhydrocarbon material of similar boiling point to said benzene, whichcomprises contacting said fraction with from 0.5% to 5.0% by weight ofsaid light oil fraction of aluminum chloride at a temperatur in therange of 0 C. to 80 C. for a period of least one hour thereby causingthe,

formation of resinous polymer from a portion of said polymerizableunsaturated hydrocarbon material, neutralizing said aluminum chloride,separatingsaid fraction from the resulting reaction mass including saidpolymer, thereafter contacting said fraction witha further quantity offrom 0.5% to 5.0% by weight of said light oil fraction of aluminumchloride at a temperature in the range 0 C. to 80 C. for a period of'atleast one hour thereby causing the formation ofoily polymer from theremaining .polymerizabie unsaturated hydrocarbon material present,neutralizing said further quantity of aluminum a portionof saidpolymerizable unsaturated from portion of said impurity, neutralizingsaid 'r' l2 8. A process for the recovery of a mixture of benzene andtoluene from alight oil fraction containing the same together withpolymerizabie unsaturated hydrocarbon material of similar boiling pointto said mixture which comprises contacting said fraction with from 0.5%to 5.0% by weight of said light oil fraction of aluminum chlorde at atemperatur in the range of 0 C. to

80 C. for a period of at least one hour thereby causing the formation ofresinous polymer from a portion of said polymerizable unsaturatedhydrocarbon material, neutralizing said aluminum chloride, separatingsaid polymer and said fraction from the resulting reaction-mass and fromeach. other, thereafter contacting said fraction with a further quantityof from 0.5% to 5.0% by weight of said light oil fraction or alu-' minumchloride at a temperature in the range of 0 C. to 80 C. for a period ofat least one hour thereby causing the formation of oily polymer from theremaining polymerizable unsaturated hydrocarbon ma erial present,neutralizing said further quantity of aluminum chloride, and recoveringa mixture of benzen and toluene in 5 more concentrated form from theresulting reaction mass. i

- A process for refining aromatic hydrocarbon material boiling below 400C. and contaminated with polymerizable impurity of similar boiling pointtherewith, which comprises contacting'saidcontaminated aromatichydrocarbon material with an acid-acting metallic halide catalyst u'nder conditions causing the formation of polymer catalyst, separatingsaid aromatic hydrocarbon material from the resulting reaction massincludchloride and recovering benzene in more concentrated form from theresulting reaction mass.

' 7. A process for the recovery of refined toluene from'a light oil'fraction containing toluene to-.

gether with polymerizable unsaturated hydrocarbon material of similarboiling point to said toluene, which comprises contacting said frac-'tion with from 0.5% to. 5.0% by weight of said light oil fraction ofaluminum chloride at a-temvperature in the range of 0 C.'to 80 C. for asaid polymerizabieunsaturated hydrocarbonmaterial, neutralizing saidaluminum-chloride, seping 'saidpolymer, thereafter contacting saidaromatic hydrocarbon material with additional acidacting metallic,halide catalyst under conditions causing the formation of additionalpolymer,

neutralizing said additional catalyst, and separating said aromatichydrocarbon material from the resulting reaction mass.

10. A process for refining aromatic hydrocarbon 46 material boilingbelow 400 C. and contaminated with polymerizable impurity of similarboiling point therewith, which comprises contacting said confiaminated"aromatic hydrocarbon material wit an acid-acting metallic halidecatalyst un- 50 der conditionscausing the formation of polymer aratingsaid fraction from the resulting reaction mass including said polymer,thereafter contact-' ing said fraction with a further quantity of from0.5% to 5.0% by weight of said light oil fraction of aluminum chlorideat a temperature in the from a portion of said impurity, neutralizingsaid catalyst, separating-said polymer and saidaromatic hydrocarbonmaterial from the resulting reaction mass and from each other,thereafter iii! contacting said aromatic hydrocarbon material range of 0C. to Cifor a period of at least one hour thereby causing the formationof oily polymer from the remaining polymerizable un- 00 polymer and saidaromatic hydrocarbon material saturated hydrocarbonmaterial present,neutralizing said further quantity of aluminum chloride, and recoveringtoluene in more concentrated formfrcm the resulting reaction mass.

mauxasonar.

w t additional acid-acting metallic halide catalyst under conditionscausing the formation of additional polymer neutralizing said additionalcatalyst. and'separating said additional from th'resulting reaction massand from each other.

